Separating labs version from jclouds version

Tested by running `mvn clean install` from `labs`. This commit should have done the following:

1. Added a new `jclouds-labs-project` parent for all labs projects that sets a `jclouds.version` property
2. Made all labs projects listed in the aggregator depend on **this** parent rather than `jclouds-project` directly
3. Updated all the dependencies so that a) labs dependencies use `project.version` b) non-labs jclouds dependencies use `jclouds.version`
4. Updated the OSGi imports to use `jclouds.version` for any non-labs packages

Please help verify, at least by checking out and running `mvn clean install` from labs. Thanks!